Levels of macroelements and toxic elements in herbal teas

Abstract

A total of 14 diverse herbal teas were examined, including: yarrow, basil, St.John’s wort, peppermint, horsetail, nettle, thyme, corn silk, hibiscus, marshmallow, chamomile, rosehip, heather and wild mint. The samples were prepared using the method of microwave digestion, and measurements were performed by the use of inductively coupled plasma mass spectrometry (Cd, Hg, Pb, As, Sb); atomic absorption spectrometry (Mg); emission flame photometry (Ca, K, Na) and spectrophotometry (P). Intervals of variation (mg/kg) for macroelements were: Ca (2738-35399); P (1545-6264); Mg (1647-7816); Na (293-10629) and K (9683-33985), and for toxic elements: Cd (0.014-0.645); Hg (<0.001- 0.017); Pb (0.064-1.340); As (0.030-0.544) and Sb (0.004-0.068). In the three samples (yarrow and two St.John’s wort samples) measured cadmium concentration was higher than the maximum level for dried herbs, recommended by WHO. Ward's hierarchical clustering method was performed with the aim of grouping herbal teas by the amount of toxic elements. [Projekat Ministarstva nauke Republike Srbije, br. TR31071]

Keywords

• herbal teas
• macroelements
• toxic elements
• ICP-MS
• AAS